Cryocoolers are often used to cool various components to extremely low temperatures. For example, cryocoolers can be used to cool focal plane arrays in different space and airborne imaging systems. There are various types of cryocoolers having differing designs, such as pulse tube cryocoolers, Stirling cryocoolers, and Gifford-McMahon cryocoolers. These types of cryocoolers typically include a regenerator, which represents a porous material through which fluid (such as liquid or gas) flows back and forth. Heat is stored in and released from the regenerator as the fluid flows back and forth to support the cooling operations of a cryocooler.
A cryocooler typically has a “warm” end and a “cold” end, where the ends represent different portions of the cryocooler that are at different temperatures. A regenerator is often located between the warm end and the cold end of a cryocooler. Any heat flow within a regenerator between the warm and cold ends of a cryocooler reduces the overall cooling capacity and effectiveness of the cryocooler. However, simply using materials with low thermal conductivities in a regenerator may not be possible. Many materials with low thermal conductivities do not possess an adequate volumetric heat capacity needed to form an efficient regenerator for a cryocooler.